Consider characters limit on the comments

[ghost]

We may need to consider some options regarding the comments, since we're working on a sidebar level we need to encourage the users to keep comments really short almost as 'tweet', this will help keep objectivity on each comment and provide a great scan for the discussion/thread.

If this is not a valid option, we may need to predict the way we display longer comments (with view full comment hint) and use the add comment section (maybe with scroll), but this is something I'd suggest avoid.

@satazor @marcooliveira @diasdavid